The present invention is directed to a quality control mechanism and process in a multi-ejector system, and more particularly, to ensuring the quality of a printed biological assay consisting of a plurality of biofluid drops ejected by the multi-ejector system.
Many scientific tests such as those directed to biology, genetics, pharmacology and medicine, employ sequences or arrays of biofluid drops on which the tests are to be performed. In some testing applications up to several thousand biofluid drops can be deposited onto a single substrate where a single substrate contains a variety of unique known biofluids. For example, in current biological testing for genetic defects and other biochemical aberrations, thousands of the individual biofluids may be placed on a substrate. Thereafter, additional biofluids are deposited on the previously deposited drops to initiate interactions. This treated biological assay is then scanned in order to observe changes in physical properties of the fluids.
If the biological assay is defective, testing undertaken with the biological assay is invalid, resulting in false and potentially dangerous consequences. It is therefore critical the biological assay has the appropriate biofluid deposited at the appropriate locations, in appropriate amounts.
Quality control mechanisms and processes are not now available which provide the high quality assurance for large-drop assays, in an economical manner.
A method and mechanism for ensuring quality control in printed biological assays is provided. A multi-ejector system having a plurality of individual drop ejectors is loaded with a variety of biofluids. The biofluids include at least a carrier fluid, a biological material to be used in the testing, and markers, such as fluorescent dyes. Data regarding the biofluid loaded in each of the drop ejectors is stored along with an expected signature output of the biofluid. Particularly, the signature output represents signals from individual ones of the fluorescent markers included within the biofluid. Once a biological assay consisting of the biofluid drops has been printed, a scanner capable of detecting the markers scans the biological assay and obtains actual signature output signals for each of the drops of the biological assay. A comparing operation is undertaken to compare the obtained signature output through the scanning operation, with the expected signature output signals for the biofluid loaded in the corresponding drop ejector. The biological material itself may also be tagged with a marker to ensure its inclusion in the biofluid. Implementation of the comparing operation makes it possible to verify the biofluids were loaded in the proper drop ejector, including the proper biological material, and that the drop ejectors are functioning properly.